The use of signal processing techniques to enhance the reproduction of sounds from multiple sound reproducers, for example, multiple loudspeakers, is well documented. There are, for example, the systems disclosed in U.S. Pat. Nos. 4,893,342; 4,910,779; 4,975,954; 5,034,983; 5,136,651; and, 5,333,200, and the references cited in these patents.
Referring, for example, to U.S. Pat. Nos. 4,975,954 and 5,333,200, the systems disclosed in these patents are capable of reducing crosstalk among multiple sound sources which project sound into a common environment. Such an environment exists inside of a listening room or an automotive vehicle passenger compartment served by multiple loudspeakers playing back, for example, different frequency components of a common program.